KR20070089855A - Cigarette with carbon on tow filter - Google Patents

Abstract

A cigarette (10) comprises a tobacco rod (12) and a carbon-on-tow filter (14) comprising a fiber tow (18) with flavored or unflavored carbon particles (20) distributed throughout the tow. The carbon particles have high activity in the range of 90 to 115%, preferably 95%. As mainstream smoke is drawn through the filter (14), gas phase smoke constituents are removed and flavor is released when the particles are flavored. Ventilation (24) is provided to limit the amount of tobacco being combusted during each puff and such ventilation is arranged at a location near the downstream end of the carbon-on-tow filter to lower mainstream smoke velocity through the filter. The filter achieves significant reductions in gas phase constituents of mainstream smoke, including 90% reductions or greater in at least one of 1, 3 butadiene, acrolein, isoprene, propionaldehyde, acrylonitrile, benzene, toluene, and 80% reductions or greater in acetaldehyde over extended shelf life of the cigarettes.

Description

Cigarette with carbon on toe filter {CIGARETTE WITH CARBON ON TOW FILTER}

FIELD OF THE INVENTION The present invention relates to smoking articles, such as cigarettes, and in particular to cigarettes comprising filter segments comprising adsorbents and fibrous filter materials arranged to favor removal of gas phase components from mainstream smoke over an extended cigarette shelf life. It is about.

Smoking articles, in particular cigarettes, generally comprise tobacco rods of ground tobacco (usually in the form of cut fillers) surrounded by paper wrappers and cylindrical filters aligned end to end with tobacco rods. Typically, the filter comprises a plug of cellulose acetate tow attached to the tobacco rod by tipping paper. Ventilation of the mainstream smoke is accomplished with a row or rows of holes near the location along the filter. This ventilator provides dilution of mainstream smoke sucked into the ambient air to reduce tar transport.

When a cigarette is lit, the smoker breathes mainstream smoke from the coal at the lit end of the cigarette. The inhaled cigarette smoke first enters the upstream end portion of the filter and then passes through the downstream portion adjacent the oral (mouth) end of the cigarette.

Some cigarettes have filter fragments incorporating adsorbent material such as activated carbon, examples of which are described in Tovey, US Pat. No. 2,881,770; 3,353,543 to Sproull et al .; 3,101,723 to Seligman et al .; 4,481,958 to Ranier et al. Any commercially available filters have particles or granules (eg, activated carbon material) of carbon, alone or dispersed in cellulose acetate tow; Other commercially available filters have carbon threads dispersed therein; On the other hand, other commercially available filters have a so-called "plug-space-plug", "cavity filter" or "triple filter" design. Examples of commercially available filters include SCS IV Dual Solid Charcoal Filter and Triple Solid Charcoal Filter from Filtrona International, Ltd .; Triple Cavity Filter from Baumgartner; And ACT from Filtrona International, Ltd. See also Clarke et al., World Tobacco, page 55 (November, 1992). Details of the properties and compositions of cigarettes and filters are described in US Pat. Nos. 5,404,890 and 5,568,819 to Gentry et al., Which are incorporated herein by reference.

Conventional typical practice with "plug-space-plug" type cigarettes has allowed the ventilator to be positioned in a position along the adsorbent bed contained so far in order to obtain sufficient space in the ventilator aperture from the oral end of the filter. By doing so, the smoker's lips could not block the vent holes. However, this arrangement tends to lower the filtration efficiency of the adsorbent because it tends to increase the rate of mainstream smoke in at least one portion of the adsorbent bed.

Various annular arrangements of filters with carbon-bearing annular filter sites have been disclosed in the art. For example, European Patent No. 579,410 has shown a number of embodiments of cigarettes having cyclic carbon-bearing sites surrounded by either hollow filtration materials or hollow tubular cavities formed by gas phase porous membranes. Similarly, US Pat. No. 3,894,545 to Crellin et al. Showed various arrangements of cyclic carbon-bearing sites surrounded by gas phase porous membranes or rods of carbon-bearing material surrounded by gas phase porous membranes.

Cigarette filter elements incorporating carbon have the ability to remove the components of the mainstream smoke passing through it. In particular, activated carbon has a tendency to reduce the level of certain gas phase components present in the mainstream smoke, which causes a change in the properties of the sensory organs of smoking.

Despite these advantages of carbon-bearing filters, they have not been widely used until now. In previous arrangements, the mainstream smoke from carbon filters tends to have a flavor record that is contrary to the consumer's preferences, and therefore their use in commercially available cigarettes has been found to be not widespread so far. Plasticizers in fiber tow filters also tend to degrade certain carbon components over time, thereby reducing the effectiveness of the carbon to remove gas phase components over the extended shelf life of cigarettes comprising such filter arrangements.

It is desirable to provide a cigarette having other material that absorbs and / or adsorbs gas phase components present in carbon and / or mainstream smoke smoke while providing good absorption / adsorption, dilution, and inhalation properties.

In addition, the pressure at the dilution site and downstream of the adsorbent / absorbent to provide an acceptable inhalation characteristic of the puff of smoke having a reduced gas phase component but with an acceptable taste and resistance-to-draw. It is desirable to provide such a filter having a desired residence time at the site containing the absorbent / adsorbent while simultaneously achieving a reduction.

Smoking articles such as cigarettes according to the present invention comprise a multi-component filter comprising a fiber tow having particles of high-activated carbon on the tobacco rod and the tow. In a preferred embodiment, the activated carbon also has a flavoring agent and comprises high-activated carbon particles on the fibrous tow. When inhaling mainstream smoke through the top of the filter, the gaseous smoke components were removed and the flavourant was released from the activated carbon. Ventilation devices are provided to limit the amount of tobacco burned during each puff, which is arranged downstream of most of the carbon on the tow to further lower the mainstream smoke rate through the adsorbent. Highly activated carbon particles on cellulose acetate tow are mainstream smoke gas phases including at least 90% reduction in 1,3 butadiene, acrolein, isoprene, propionaldehyde, acrylonitrile, benzene, toluene and at least 80% reduction in acetaldehyde It is known to achieve a significant reduction of the components.

Advantageously, the present invention achieves an optimal residence time for smoking at the site of the filter with the adsorbent material, and also achieves good dilution of the smoke by ambient air and provides the resistance to acceptable inhalation expected for most smokers. The derivation is derived.

Other advantages and features of the present invention, in conjunction with the foregoing, will be evident later, the nature of which will be more clearly understood by reference to the following detailed description of the invention, the appended claims and the various illustrations shown in the drawings. .

In addition to what has been described above, the novel features and advantages of the present invention will become apparent to those skilled in the art from the following detailed description in conjunction with the accompanying drawings, in which like reference features refer to similar parts.

1 is a front side view of a cigarette rod and a portion thereof separated to show a cigarette and an interior item comprising a multi-component filter comprising high-activated carbon particles on a fiber tow according to the present invention.

2 is a front side view of a portion of them separated to show other cigarettes and internal items comprising a multi-component filter comprising high-activated carbon particles on tobacco rods and fiber toes according to the present invention.

FIG. 3 is a view of a portion of those separated to show other cigarettes and internal items comprising a multi-component filter comprising high-activated carbon particles on a fiber tow having a tobacco rod and a lower flavoring additive according to the invention. Front side view.

FIG. 4 is a part of them separated to show another cigarette and an inner item comprising a multi-component filter comprising high-activated carbon particles on a fiber tow with a tobacco rod and a lower flavoring additive according to the invention. This is a side view of.

Referring to FIG. 1, a preferred embodiment of the present invention includes a rod 12 of smokeable material, such as crushed tobacco, and a multi-component filter 14 attached to the rod 12 by tipping paper 16. To provide a cigarette (10). When the cigarette 10 is lit, mainstream smoke is generated from the tobacco rod 12 and sucked through the filter 14.

Here, the relative positions of "upstream" and "downstream" between the filter fragment and other features have been described in relation to the direction of the mainstream smoke as it is drawn from the tobacco rod 12 through the multi-component filter 14.

Preferably, filter 14 comprises cellulose acetate tow 18 comprising a suitable plasticizer such as triacetin with highly activated carbon particles on granules 20 distributed through the tow. The oral distal (mousepiece) component 22 is downstream of the tow 18 and carbon 20.

The oral end (oral) component 22 is preferably in the form of a cellulose acetate plug or other suitable fibrous or web material that mitigates low particulate efficacy. Preferably, the efficacy of the particulates was low by selecting denier and total denier to obtain the desired total RTD of the multi-component filter 14.

Preferably, the carbon 20 on the tow 18 is in the form of granules or the like. Preferably, the carbon of the preferred embodiment is a high surface area, activated carbon, for example-carbon based on coconut shells of finer size or general ASTM mesh sizes used in the cigarette industry. Activated carbon includes mainstream smoke components, in particular aldehydes, ketones and other volatile organic compounds, inter alia 1,3 butadiene, acrolein, isoprene, propionaldehyde, acrylonitrile, benzene, toluene, styrene, acetaldehyde and hydrogen cyanide To adsorb the gas phase components.

With regard to the carbon particles 20, they preferably have a mesh size of 10 to 80, more preferably a mesh size of 20 to 70. Moreover, as described above, the carbon particles were highly activated to have total activity within the range of 90-110% with a target activity of about 95% as measured by the CTC (carbon tetrachloride) methodology.

The carbon particles 20 may be flavored or otherwise impregnated, such that the adsorbent particles not only remove one or more gaseous smoke components from the mainstream smoke, but also release the flavoring agent into the mainstream smoke stream. Preferably, the flavoring agent is added to the carbon granules by spraying the flavoring agent on a batch of activated carbon in a mixing (tumbling) drum, or optionally in a fluidized bed with nitrogen as a fluidizing agent, where the flavoring The agent can then be sprayed onto the carbon of the bed. Flavor addition was performed before the carbon granules were distributed through the tow 18.

Preferably, one or more rows of circumferences of the holes 24 are formed through the tipping paper 16 at locations along the downstream end portions of carbon on the tows 18, 20. The preferred arrangement maximizes the distance between the oral end of the cigarette and the hole 24, which is preferably at least 12 mm (millimeters) so that the smoker's lips do not block the hole 24.

Preferably, the level of ventilation device is in the range of 40-60%, more preferably about 45-55%, in the 6 mg FTD tar transport cigarette.

Ventilation devices are known to not only provide dilution of mainstream smoke, but also affect the reduction of the amount of cigarettes burned during each puff when combined with the low particulate efficiency filter 14. Ventilation reduces the inhalation action on the nose and thereby reduces the amount of cigarettes burned during one puff. As a result, the absolute amount of smoke components was reduced.

Advantageously, the holes 24 of the present invention downstream of the carbon on the tow filter to reduce the rate of mainstream smoke through most of the carbon particles 20 and to increase the dwell time of the mainstream smoke in the carbon 20. Located in the distal region. In addition, the additional residence time increases the efficacy of activated carbon on the reduction of the target mainstream smoke component. The smoke passes through the hole 24 and is diluted by ambient air mixing with the mainstream smoke to achieve air dilution in the range of about 45-65%. For example, at 50% air dilution, the flow through the cigarette upstream of the dilution hole was reduced by 50% and thus the smoke rate was reduced by 50%.

Preferably, the ranged carbon loading 20 on the tow 18 comprises at least 90-120 mg (milligram) or more with a target loading of about 120 mg. This carbon loading is significant in mainstream smoke gas phase components including a 90% or more reduction in 1,3 butadiene, acrolein, isoprene, propionaldehyde, acrylonitrile, benzene, toluene, and a 80% or more reduction in acetaldehyde. Provides a savory cigarette that achieves a reduction. Increased carbon loading also ensures adequate activity levels sufficient to achieve this reduction over the expected shelf life of the product (6 months or longer).

There is no significant adverse effect from the plasticizers (eg triacetin) used on the fiber tow 18, with a target carbon activity in the range of 90-110% and about 95%. When the fiber tow 18 is cellulose acetate with a triacetin plasticizer, the level of triacetin can be any necessary level (usually about 6%) and this level adversely affects the above described proportion reduction of the gas phase components of the mainstream smoke. I never do that. In this carbon activity ratio, there is no significant deactivation of carbon over the shelf-life of the cigarette product, whereby a decrease in the proportion of gas phase components occurs over the entire shelf-life period. Cigarettes with an extended shelf-life of 12 months have almost the same efficacy as cigarettes that are 1 month old.

As an example, the length of the tobacco rod 12 is preferably 49 mm, and the length of the multi-component filter 14 is preferably 34 mm. The length of the carbon on the tow fragment is preferably 20-26 mm, and the cellulose acetate plug 8 at the filter 14 end is preferably 8 mm. The overall level of tar (FTC) is preferably in the range of 6 mg in 6 or more puffs.

The tobacco rod 12 may be wrapped in a conventional cigarette wrapper or a banded paper may be used for this purpose. The strip-shaped cigarette paper incorporates integrated cellulose surrounding the finished tobacco rod of the cigarette 10 to alter the mass burning rate of the cigarette to reduce the risk of the substrate igniting if the cigarette 10 is left smoking immediately. Apart from the band at regular intervals. U.S. Patent Nos. 5,263,999 and 5,997,691 describe strip-shaped cigarette papers, all of which are incorporated herein.

In the preferred embodiment 10 of FIG. 1, 90-120 milligrams, preferably about 120 milligrams, of the high-activated flavor carbon 20 was distributed over the fiber tow 18. Optional flavourant loading is 3-6 mg in carbon 20, more preferably about 4 or 5 mg. It has been shown that up to about 6 mg flavor system per 120 mg of carbon has no adverse effect on component removal. Here, reference to 120 mg loading of flavored carbon can be understood to include any flavoring agent. In addition, as described above, carbon activity is in the range of 90-110% with a target of about 95%. Although the plasticizer in the tow 18 is about 6%, the carbon on the tow filter component retains its effectiveness on the removal of the gas phase component over the extended shelf life of the cigarette 10.

With reference to Tables I-V below, for the commercially provided cigarettes (controls), as described in the headings of each table, data are provided indicating the reduction in the average percentile of certain gas phase components in the mainstream smoke achieved with the test cigarettes. It became. For a given test cigarette, the first row of percentiles represents the average reduction achieved for the first control; The second and third rows represent the average reduction in test cigarettes after receiving simulated conditions of about 6 months of shelf-life and about 12 months of shelf-life, respectively. The accelerated aging process involves the circulation of cigarettes subjected to high-humidity and low-humidity, high temperature conditions for the period described above.

As shown in the table, even with the presence of triacetin and after a significant amount of shelf-life of simulated natural ripening of about one year, a significant reduction in gaseous and smoke components was achieved by 120 milligrams of carbon in the tow phase.

2 shows a cigarette 10A with a short tow 18A and a loading of reduced carbon particles 20A distributed between the tows. The carbon loading is about 75 milligrams and the carbon has no flavor. Carbon activity is in the range of 90-115% with a target of about 95%.

With reference to FIGS. 3 and 4, alternative preferred embodiments further preferably have a cigarette (10B) having a carbon loading of about 75 to 120 milligrams or an increased activity level (90 to 110% with a target activity of about 95%). Cigarettes (10B, 10C) comprising about 120 milligrams of such carbon in), about 75 milligrams of such carbon in cigarette (10C), carbon-on-toe filter plugs 18 with carbon loading, both free of flavors It includes. About 90 mg carbon is the preferred amount. In this embodiment, the filters further comprise flavor release elements 32, 32A at a position downstream of the carbon-on-toe (in the sense of direction as the mainstream smoke inhaled through the cigarette), as shown in FIG. 3. Filter plug 32 has single yarn 33 (as described generally in US Pat. No. 6,761,174) with a flavourant therein or a bed of flavourant-releasing particles 35 as shown in FIG. The particles may be arranged as a plug of fiber tow having flavor-releasing particles placed in or in the space of the component 32 plug-space-plug arrangement.

These cigarettes 10B, 10C of FIGS. 3 and 4, with increased carbon loading and increased carbon activity levels, provide enhanced ability to remove gaseous smoke constituents, acceptable storage-life and desirable sensory characteristics. do.

In addition, the present invention can be practiced not only for large sizes but also for narrow, various columnar cigarettes. In addition, although the present invention is preferably carried out with no flavored tobacco rods, flavored tobacco material can also be envisaged.

Claims (12)

A cigarette comprising a carbon-on-toe filter comprising a fiber tow having carbon particles distributed between the tobacco rod and the tow, wherein the carbon-on-toe filter is one or more from tobacco mainstream smoke when the mainstream smoke is sucked through the filter. And configured to substantially remove smoke constituents, and wherein the carbon particles have an activity in the range of 90-115%. The cigarette of claim 1, wherein the carbon comprises from about 75 to 120 milligrams or more. 3. The cigarette of claim 2 wherein the carbon particles are flavored. The cigarette of claim 1, wherein the carbon comprises about 120 milligrams. The cigarette of claim 4, wherein the carbon particles are flavored. The cigarette of claim 1, wherein the carbon particles have an activity of about 95%. The cigarette of claim 1, wherein the filter comprises a ventilator and the ventilator is in the range of 45-55%, wherein the oral end filter component is downstream of the carbon-on-toe filter component. 8. The cigarette of claim 7, wherein the ventilator comprises one or more circumferential rows of holes through the tipping paper, wherein the tipping paper attaches a carbon-on-toe filter to the tobacco rod. The cigarette of claim 8, wherein the ventilator is located at least 12 mm from the oral end of the cigarette. The method of claim 1, wherein the carbon-on-toe filter is 90% in at least one of 1,3 butadiene, acrolein, isoprene, propionaldehyde, acrylonitrile, benzene and toluene over an extended shelf life of at least 6 months. A cigarette that achieves a significant reduction in the gas phase components of the mainstream smoke, including a reduction or more. The cigarette of claim 1, wherein the carbon-on-toe filter achieves a significant reduction in the gas phase components of the mainstream smoke, including a reduction of at least 80% of acetaldehyde. The cigarette of claim 1, wherein the filter comprises a flavor release element located downstream of the carbon-on-tow.

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